School & District Management

How Many People Really Have Autism?

By Nirvi Shah — May 10, 2011 2 min read
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How many people really have autism? New studies are changing what people believe about how prevalent this condition really is.

In the United States, the Centers for Disease Control and Prevention reports that between 1 in 80 and 1 in 240—for an average of 1 in 110 children have an autism spectrum disorder.

But a study published Monday in the American Journal of Psychiatry found a much higher rate: about 1 in 38 children.

The study involved testing all the 7- to 12-year-old children, some 55,266 kids, in a single South Korean town. The 12 researchers concluded that two-thirds of the cases they found were undiagnosed, with students in typical classes with no special services. “These findings suggest that rigorous screening and comprehensive population coverage are necessary to produce more accurate [autism spectrum disorder] prevalence estimates and underscore the need for better detection, assessment, and services,” they wrote.

If autism is truly more prevalent than we now think, then the implications for schools and society could be huge. Undiagnosed students who aren’t getting services and therapy that could help them flourish may instead be floundering.

On the other hand, another study of a community in England found that the autism epidemic believed to be taking place may not be one at all. That study, also published this month but in the Archives of General Psychiatry, involved about 7,400 British adults.

“If the prevalence of autism is increasing, rates in older adults would be expected to be lower than rates among younger adults,” the researchers hypothesized.

But they found that about 1 percent of adults have autism, a number that’s similar to what the CDC estimates, and they concluded that testing adults for autism is possible.

I am not a research expert so I can’t say whether the studies truly conflict with one another. The two studies involve different numbers of people in different countries, although both used an initial screening of some kind, a questionnaire or interview, and followed up with diagnostic assessments.

Does all of this mean that the rate of autism is holding steady, but we just don’t have an accurate picture of what the rate really is? Does it mean that what may seem like autism to one person is not autism to another?

I think it may mean that, like life before these studies were published, we still have a lot to learn about this diagnosis and how to best provide for those who have it.

A version of this news article first appeared in the On Special Education blog.